Electro-optical device, method of manufacturing electro-optical device, and electronic apparatus

ABSTRACT

An electro-optical device is configured by a laminated body of a second conductive layer and a reflective layer for a mirror. The second conductive layer includes a mirror support post facing a concave portion at a side opposite to a substrate, and a flat plate which extends from an end portion of the mirror support post and faces the substrate. The concave portion is filled with the resin. Surfaces of the flat plate and the resin configure a continuous plane. The reflective layer for a mirror is laminated on a surface of the resin at a side opposite to the substrate, and a surface of the flat plate of the second conductive layer at a side opposite to the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentSer. No. 15/867,178, filed Jan. 10, 2018, which is a continuationapplication of U.S. patent application Ser. No. 15/059,707, filed onMar. 3, 2016, which claims priority to Japanese Patent Application JP2015-074871, filed Apr. 1, 2015. The entire disclosures of each of theabove are hereby incorporated by reference herein.

BACKGROUND 1. Technical Field

Various embodiments of the present invention relate to anelectro-optical device including a mirror, a method of manufacturing theelectro-optical device, and an electronic apparatus.

2. Related Art

For example, a projection display device, which modulates light emittedfrom a light source using a plurality of mirrors (micro mirrors) of anelectro-optical device called a digital mirror device (DMD), enlargesthe modulated light to project using a projection optical system,thereby displaying an image onto a screen, is known as an electronicapparatus. In the electro-optical device which is used for theelectronic apparatus, the mirror is supported by a torsion hinge (twisthinge) through a mirror support post (mirror post), and is electricallycoupled to the torsion hinge. In addition, the torsion hinge issupported by a bias electrode on a substrate side which is formed in thesubstrate through a hinge support post, and is electrically coupled tothe bias electrode on a substrate side. Thus, while a bias voltage isapplied to the mirror from the bias electrode on a substrate side, if adrive voltage is applied to an address electrode, it is possible todrive the mirror using an electrostatic force which is generated betweenthe mirror and the address electrode.

Here, if the mirror support post faces the concave portion at a sideopposite to the substrate, a large dent is formed on a surface of themirror, and thereby reflectance of the surface (reflective surface) ofthe mirror decreases. Thus, a technology, in which an inorganic materialis accumulated to a surface of the mirror post, the sacrificial layer orthe like, the surface is ground, and thereafter the reflective film thatforms the mirror is formed, is proposed (refer to JP-T-2007-510174 andJP-A-2005-115370).

However, in order to fill a concave portion with an inorganic material,it is necessary to quite thickly accumulate the inorganic material, andin a case of the inorganic material, grinding speed is decreased, andthus a long processing time is required to grind the inorganic materialfor removal from a surface of a sacrificial layer or the like.

SUMMARY

An advantage of some aspects of the invention is to provide anelectro-optical device in which a concave portion of a mirror supportpost (mirror post) is efficiently filled and which prevents a large dentfrom being formed on a surface of the mirror, a method of manufacturingthe electro-optical device, and an electronic apparatus.

According to one aspect of the invention, there is provided anelectro-optical device including: a substrate; a first conductive layerwhich includes a first support post (hinge post) that protrudes towardthe substrate at a side of the substrate and that is supported by thesubstrate, and a torsion hinge (twist hinge) a second conductive layerfor a mirror which includes a second support post (mirror support post)that faces a concave portion at a side opposite to the substrate andprotrudes toward a side opposite to the substrate from the torsionhinge, and a flat plate that extends from an end portion located at aside of the second support post opposite to the substrate and faces thesubstrate; a resin which fills an inner side of the concave portion; anda reflective layer for a mirror which is laminated on a surface of theresin at a side opposite to the substrate and a surface of the flatplate at a side opposite to the substrate, and configures a mirrortogether with the second conductive layer for a mirror.

In one or more embodiments of the invention, the second support postfaces the concave portion at a side opposite to the substrate, but theconcave portion is filled with the resin, and thus a large dent ishardly formed on the surface of the mirror. Accordingly, it is possibleto increase utilization efficiency of light, and to prevent contrastfrom lowering due to scattering at the mirror. In addition, in a case inwhich the concave portion is filled with the resin, the concave portioncan be intensively filled, and thus a planarization step can be omitted.In addition, even in a case in which the planarization step cannot beomitted, the resin formed on a surface of the sacrificial layer formedaround the concave portion is thinned, and if the resin is used, agrinding speed is increased. Thus, the concave portion of the secondsupport post can be efficiently filled, and it is possible to prevent alarge dent from being formed on the surface of the mirror.

In the electro-optical device, it is preferable that a height differencebetween a height from the torsion hinge to a surface of the resin at aside opposite to the substrate, and a height from the torsion hinge to asurface of the flat plate at a side opposite to the substrate is equalto or less than 0.2 μm. With a difference of such a degree, a decreaseof utilization efficiency of light and a decrease of contrast due toscattering at a mirror is not noticeable.

In the electro-optical device, it is preferable that a surface of theresin at a side opposite to the substrate and a surface of the flatplate at a side opposite to the substrate configure a continuous plane.

In the electro-optical device, it is preferable that the secondconductive layer for a mirror is thicker than the reflective layer for amirror. According to the configuration, it is possible to reliably applya proper potential to the mirror.

Even in this case, it is preferable that the sum of the thicknesses ofthe second conductive layer for a mirror and the reflective layer for amirror is from 0.2 μm to 0.5 μm.

In the electro-optical device, it is preferable that the resin hasconductivity. According to the configuration, it is possible to reliablyapply a proper potential to the mirror.

In the electro-optical device, it is preferable that the resin is formedof a photosensitive resin. According to the configuration, it ispossible to make the resin selectively remain in an arbitrary position.

According to another aspect of the invention, there is provided a methodof manufacturing an electro-optical device including: forming a firstsacrificial layer in which a first opening (opening for an hinge post)is provided at a side of a substrate; forming a first conductive film ata side of the first sacrificial layer opposite to the substrate and aninternal side of the first opening; forming a torsion hinge (twisthinge) which includes a first support post (hinge post) that isconfigured by the first conductive film formed on an internal side ofthe first opening, by patterning the first conductive film; forming asecond sacrificial layer in which a second opening (opening for a mirrorsupport post) is provided at a side of the torsion hinge opposite to thesubstrate; forming a second conductive film at a side of the secondsacrificial layer opposite to the substrate and an internal side of thesecond opening; filling a concave portion which is formed in the secondconductive film by the second opening with a resin; forming a reflectivemetal film on surfaces of the second conductive film and the resin at aside opposite to the substrate; and forming a mirror by patterning thesecond conductive film and the reflective metal film.

In the method of manufacturing an electro-optical device, it ispreferable that planarizing surfaces of the second conductive film andthe resin at a side opposite to the substrate, between the filling andthe forming of the reflective metal film is further included.

In the method of manufacturing an electro-optical device, it ispreferable that, in the filling, the concave portion is coated with aliquid resin material and thereafter the resin material is cured.

An electro-optical device which employs one or more embodiments of theinvention can be used for various types of electronic apparatuses, andin this case, a light source unit which emits light source light to themirror is provided in the electronic apparatus. In addition, if aprojection type display device or a head-mounted display device isconfigured as the electronic apparatus, a projection optical systemwhich projects the light modulated by the mirror is further provided inthe electronic apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention will be described with reference tothe accompanying drawings, wherein like numbers reference like elements.

FIG. 1 is a schematic view illustrating an optical system of aprojection type display device serving as an electronic apparatus whichemploys an embodiment of the invention.

FIGS. 2A and 2B are explanatory views schematically illustrating a basicconfiguration of an electro-optical device which employs an embodimentof the invention.

FIGS. 3A and 3B are explanatory views schematically illustrating crosssections IIIA-IIIA and IIIB-IIIB of a principal portion of theelectro-optical device which employs an embodiment of the invention.

FIG. 4 is a cross-sectional view illustrating a specific configurationof the electro-optical device which employs an embodiment of theinvention.

FIGS. 5A to 5F are step sectional views illustrating a manufacturingmethod of the electro-optical device which employs an embodiment of theinvention.

FIGS. 6A to 6C are step sectional views illustrating a manufacturingmethod of the electro-optical device which employs an embodiment of theinvention.

FIGS. 7A to 7D are step sectional views illustrating a manufacturingmethod of the electro-optical device which employs an embodiment of theinvention.

FIGS. 8A to 8F are plan views of layers formed by manufacturing steps ofthe electro-optical device which employs an embodiment of the invention.

FIGS. 9A to 9E are plan views of layers formed by the manufacturingsteps of the electro-optical device which employs an embodiment of theinvention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the invention will be described with reference to thedrawings. In the following description, a projection type display deviceserving as an electronic apparatus which employs one or more embodimentsof the invention will be described. In addition, in the figures referredto by the following description, each layer and each member isillustrated in a recognizable size in the figures, and scales aredifferent from each other for each layer and each member. In addition,the number of mirrors or the like is reductively illustrated in thedrawings.

Projection Type Display Device Serving as Electronic Apparatus

FIG. 1 is a schematic view illustrating an optical system of aprojection type display device serving as an electronic apparatus whichemploys one or more embodiments of the invention. The projection typedisplay device 1000 illustrated in FIG. 1 includes a light source unit1002, an electro-optical device 100 which modulates light emitted fromthe light source unit 1002 in response to image information, and aprojection optical system 1004 which projects the light modulated by theelectro-optical device 100 onto an image-projected body 1100 such as ascreen as a projection image. The light source unit 1002 includes alight source 1020 and a color filter 1030. The light source 1020 emitswhite light, the color filter 1030 emits lights of various colors inaccordance with rotation, and the electro-optical device 100 modulatesthe incident light at a timing synchronous to the rotation of the colorfilter 1030. Instead of the color filter 1030, a phosphor substrate,which converts the light emitted from the light source 1020 into lightsof various colors, may be used. In addition, the light source unit 1002and the electro-optical device 100 may be provided for each light ofvarious colors.

Basic Configuration of Electro-Optical Device 100

FIGS. 2A and 2B are explanatory views schematically illustrating a basicconfiguration of the electro-optical device 100 which employs one ormore embodiments of the invention, and FIGS. 2A and 2B are respectivelyan explanatory view illustrating a principal portion of theelectro-optical device 100 and an exploded perspective view of aprincipal portion of the electro-optical device 100. FIGS. 3A and 3B areexplanatory views schematically illustrating cross sections IIIA-IIIAand IIIB-IIB of the principal portion of the electro-optical device 100which employs one or more embodiments of the invention, and FIGS. 3A and3B are respectively an explanatory view schematically illustrating astate in which a mirror is tilted to one side, and an explanatory viewschematically illustrating a state in which the mirror is tilted to theother side.

As illustrated in FIGS. 2A and 2B and FIGS. 3A and 3B, in theelectro-optical device 100, a plurality of mirrors 51 are disposed overone surface is of a substrate 1 in a matrix, and the mirrors 51 areseparated from the substrate 1. The substrate 1 is, for example, asilicon substrate. For example, each of the mirrors 51 is a micro mirrorhaving a plane size in which a length of one side thereof is, forexample, 10 μm to 30 μm. The mirrors 51 are arranged with a size of, forexample, 600×800 to 1920×1080, and one mirror 51 corresponds to onepixel of an image.

A surface of the mirror 51 is configured by a reflective surface whichis formed of a reflective metal film such as aluminum. Theelectro-optical device 100 includes a first portion 100 a having a biaselectrode 11 on the substrate side which is formed on one surface is ofthe substrate 1, and address electrodes 12 and 13 on the substrate side,a second portion 100 b having upper address electrodes 32 and 33 and atorsion hinge (twist hinge) 35, and a third portion 100 c having themirrors 51. An address circuit 14 is formed on the substrate 1 in thefirst portion 100 a. The address circuit 14 includes a memory cell forselectively controlling an operation of each mirror 51, lines 15 such asa word line and a bit line, or the like. A random access memory (RAM)having a CMOS circuit 16 includes a circuit configuration similarthereto.

The second portion 100 b includes the upper address electrodes 32 and33, the torsion hinge 35, and a mirror support post (second supportpost) 52. The upper address electrodes 32 and 33 are electricallycoupled to the address electrodes 12 and 13 on the substrate sidethrough electrode posts 321 and 331, and are supported by the addresselectrodes 12 and 13 on the substrate side. Hinge arms 36 and 37 extendfrom both ends of the torsion hinge 35. The hinge arms 36 and 37 areelectrically coupled to the bias electrode 11 on the substrate sidethrough a hinge support post (first support post) 39, and are supportedby the bias electrode 11 on the substrate side. The mirrors 51 areelectrically coupled to the torsion hinge 35 through the mirror supportpost 52, and are supported by the torsion hinge 35. Thus, the mirrors 51are electrically coupled to the bias electrode 11 on the substrate sidethrough the mirror support post 52, the torsion hinge 35, the hinge arms36 and 37, and the hinge support post 39, and receive a bias voltagewhich is applied from the bias electrode 11 on the substrate side.Stoppers 361, 362, 371, and 372, which come into contact with themirrors 51 when the mirrors 51 tilt and prevent the mirrors 51 fromcoming into contact with the upper address electrodes 32 and 33, areformed in tips of the hinge arms 36 and 37.

A drive element, which drives the mirrors 51 to tilt by generating anelectrostatic force, is configured between the address electrodes 12 and13 on the substrates side and the upper address electrodes 32 and 33,and the mirrors 51. Specifically, as illustrated in FIGS. 3A and 3B, adrive voltage is applied to the address electrodes 12 and 13 on thesubstrates side and the upper address electrodes 32 and 33, and therebywhen the mirrors 51 tilt toward the address electrode 12 and the upperaddress electrode 32, or the address electrode 13 and the upper addresselectrode 33, the torsion hinge 35 is twisted. Thus, when application ofthe drive voltage to the address electrodes 12 and 13 on the substratesside and the upper address electrodes 32 and 33 is stopped and thereby apulling force for the mirrors 51 is lost, the mirrors 51 exert a forcefor returning to a posture parallel to the substrate 1.

For example, if the mirror 51 tilts toward the address electrode 12 onthe substrate side and the upper address electrode 32 as illustrated inFIG. 3A, the electro-optical device 100 enters an ON state in which thelight emitted from the light source unit 1002 is reflected toward theprojection optical system 1004 by the mirror 51. In contrast to this, ifthe mirror 51 tilts toward the address electrode 13 on the substrateside and the upper address electrode 33 as illustrated in FIG. 3B, theelectro-optical device 100 enters an OFF state in which the lightemitted from the light source unit 1002 is reflected toward a lightabsorption device 1005 by the mirror 51. In the OFF state, the light isnot reflected toward the projection optical system 1004. The driving isperformed by each of the plurality of mirrors 51, and as the result, thelight emitted from the light source unit 1002 is modulated into imagelight by the plurality of mirrors 51, is projected from the projectionoptical system 1004, and thereby the image is displayed.

A yoke of a flat plate shape facing the address electrodes 12 and 13 onthe substrate side is provided as one piece with the torsion hinge 35,and the mirror 51 can also be driven by using an electrostatic forcewhich operates between the address electrodes 12 and 13 on the substrateside and the yoke, in addition to an electrostatic force which isgenerated between the upper address electrodes 32 and 33 and the mirror51.

Detailed Configuration of Electro-Optical Device 100

FIG. 4 is a cross-sectional view illustrating a detailed configurationof the electro-optical device 100 which employs one or more embodimentsof the invention. FIG. 4 illustrates only the second portion 100 b andthe third portion 100 c of the electro-optical device 100. Illustratingof the first portion 100 a which includes the bias electrode 11 on thesubstrate side and the address electrodes 12 and 13 on the substrateside is omitted. In addition, FIG. 4 illustrates the mirror support post(second support post) 52 and the torsion hinge (twist hinge) 35 or thelike for one mirror 51 among the plurality of mirrors 51 which areformed in the electro-optical device 100.

As illustrated in FIG. 4, the electro-optical device 100 includes thetorsion hinge 35 with conductivity which is supported on the substrate 1through the hinge support post 39 with conductivity on one surface is ofthe substrate 1. In the present embodiment, the hinge support post 39and the torsion hinge 35 are formed of a metal layer (first conductivefilm 30 which will be described later) of one piece, and the hingesupport post 39 protrudes from the metal layer (first conductive film30) toward the substrate 1. In addition, the electro-optical device 100includes the mirror support post 52 with conductivity protruded from thetorsion hinge 35 toward a side opposite to the substrate 1, and themirror 51 is coupled to an end portion 521 of the mirror support post 52at a side opposite to the substrate 1. The mirror support post 52 facesa concave portion 520 at a side opposite to the substrate 1, but theinside of the concave portion 520 is filled with a resin 41. In thepresent embodiment, the resin 41 is formed of a photo-curable resin.

The mirror 51 is configured by a laminated body in which a reflectivelayer 57 for a mirror is laminated on a conductive layer 56 for amirror. The conductive layer 56 for a mirror includes the mirror supportpost 52 and a flat plate portion 53 (a flat plate) which extends fromthe end portion 521 of the mirror support post 52 and faces thesubstrate 1, as one piece. The reflective layer 57 for a mirror islaminated on a surface 411 of the resin 41 at a side opposite to thesubstrate 1, and on a surface 531 of the flat plate 53 of the conductivelayer 56 for a mirror at a side opposite to the substrate 1 for amirror.

Here, a height difference between a height from the torsion hinge 35 tothe surface 411 of the resin 41 and a height from the torsion hinge 35to the surface 531 of the flat plate 53 of the conductive layer 56 for amirror is equal to or less than 0.2 μm. With a difference of such adegree, a decrease of utilization efficiency of light and a decrease ofcontrast due to scattering of a mirror is not noticeable. In the presentembodiment, the surface 411 of the resin 41 and the surface 531 of theflat plate 53 of the conductive layer 56 for a mirror configure (e.g.,form) a continuous plane by a CMP step which will be described later.

In the present embodiment, the conductive layer 56 for a mirror isthicker than the reflective layer 57 for a mirror. However, the sum ofthicknesses of the conductive layer 56 for a mirror and the reflectivelayer 57 for a mirror is from 0.2 μm to 0.5 μm, and the thickness is thesame as the thickness in a case in which the mirror 51 is formed as asingle film.

Manufacturing Method of Electro-Optical Device

Description will be focused on steps in which the torsion hinge (twisthinge), the mirror support post (second support post), and the mirrorare formed, among the manufacturing steps of the electro-optical device100 which employs one or more embodiments of the invention, withreference to FIG. 2B, and FIG. 5A to FIG. 9E. FIGS. 5A to 5F, FIGS. 6Ato 6C, and FIGS. 7A to 7D are step cross-sectional views illustrating amanufacturing method of the electro-optical device 100 which employs oneor more embodiments of the invention. FIGS. 8A to 8F and FIGS. 9A to 9Eare plan views of layers which are formed by the manufacturing steps ofthe electro-optical device 100 which employs one or more embodiments ofthe invention. FIG. 5A to FIG. 9E illustrate only the mirror supportpost 52 and the torsion hinge 35 for one mirror 51, among the pluralityof mirrors 51 which are formed in the electro-optical device 100. Inaddition, in the following description, a relationship between therespective sections described with reference to FIG. 2B will also beappropriately described.

First of all, as illustrated in FIG. 5A, in step ST1, the addresscircuit 14, the bias electrode 11 on the substrate side, and the addresselectrodes 12 and 13 on the substrate side, and the like, which aredescribed with reference to FIG. 2B, are formed in a wafer 10(substrate) which is configured by a silicon substrate.

Subsequently, in step ST2, a photosensitive resist layer 21 which isformed of a positive-type organic photoresist or the like is formed onone surface 10 s of a wafer 10, and thereafter, in step ST3 illustratedin FIG. 5B, exposure and development is performed for the photosensitiveresist layer 21, and a first sacrificial layer 211 including an opening(first support opening) 211 a for a hinge support post is formed. Atthis time, as illustrated in FIG. 8A, an opening 211 b for an electrodepost which is used for the electrode posts 321 and 331 of the upperaddress electrodes 32 and 33 is also formed. A thickness of the firstsacrificial layer 211 is, for example, 1 μm, and an opening diameter ofthe opening 211 a for a hinge support post is, for example,approximately 0.6 μm. The steps ST2 and ST3 are steps for forming thefirst sacrificial layer.

Subsequently, in step ST4 (step of forming a first conductive film)illustrated in FIG. 5C, a first conductive film 30 is formed on anentire surface (surface on a side opposite to the wafer 10) of the firstsacrificial layer 211 (refer to FIG. 8B). At this time, the firstconductive film is also formed on a wall surface and bottom surface ofthe opening for a hinge support post. The first conductive film 30 is,for example, a single film of an aluminum layer or a laminated film ofan aluminum layer and a titanium layer, and a thickness thereof is, forexample, 0.06 μm.

Subsequently, in step ST5 (first patterning step), in a state in which aresist mask is formed on a surface (surface on a side opposite to thewafer 10) of the first conductive film 30, the first conductive film 30is patterned, and the hinge support post 39 is formed as one piece withthe torsion hinge 35 by the first conductive film 30 remaining in theopening 211 a for a hinge support post. At this time, as illustrated inFIG. 8C, the hinge arms 36 and 37 are formed. In addition, the upperaddress electrodes 32 and 33 are simultaneously formed, and theelectrode posts 321 and 331 are formed in the opening 211 b for anelectrode post.

Subsequently, in step ST6 illustrated in FIG. 5D, a photosensitiveresist layer 22 which is formed of a positive-type organic photoresistor the like is formed on the torsion hinge 35 at a side opposite to thewafer 10, and thereafter, in step ST7 illustrated in FIG. 5E, exposureand development is performed for the photosensitive resist layer 22, anda second sacrificial layer 221 including an opening (second supportopening) 221 a for a mirror support post is formed (refer to FIG. 8D). Athickness (height) of the second sacrificial layer 221 is, for example,2 μm, and an internal diameter of the opening 221 a for a mirror supportpost is, for example, 0.8 μm. The steps ST6 and ST7 are steps forforming the second sacrificial layer.

Subsequently, in step ST8 (step of forming second conductive film)illustrated in FIG. 5F, a second conductive film 560 is formed on thesecond sacrificial layer 221 at a side opposite to the wafer 10 (referto FIG. 8E). The second conductive film 560 is, for example, a singlefilm of an aluminum layer or a laminated film of an aluminum layer and atitanium layer, and a thickness thereof is, for example, 0.25 μm.

Subsequently, in step ST9 (filling step) illustrated in FIG. 6A, a resin41 which is formed of liquid polyimide or the like is applied to thesecond conductive film 560 at a side opposite to the wafer 10, the resin41 is applied to a concave portion 520 formed in the second conductivefilm by the opening 221 a for a mirror support post (refer to FIG. 8F).Subsequently, the resin 41 is cured. Here, the resin 41 formed on anexternal side of the concave portion 520 is much thinner than the resin41 formed in the inside of the concave portion 520, and is, for example,approximately 0.5 μm.

Subsequently, in step ST10 (planarization step) illustrated in FIG. 6B,surfaces of the second conductive film 560 and the resin 41 at a sideopposite to the wafer 10 are planarized by the CMP method or the like,and the second conductive film 560 is exposed (refer to FIG. 9A). As aresult of the planarization step, surfaces of the second conductive film560 and the resin 41 at a side opposite to the wafer 10 configure acontinuous plane.

At this time, the resin 41 formed on an external side of the concaveportion 520 is much thinner than the resin 41 formed in the inside ofthe concave portion 520, and since the resin 41 has a low hardness, itis possible to perform a planarization step in a short amount of time.

Subsequently, in step ST11 (step of forming reflective metal film)illustrated in FIG. 6C, a reflective metal film 570 is formed on thesurfaces of the second conductive film 560 and the resin 41 at a sideopposite to the wafer 10 (refer to FIG. 9B). The reflective metal film570 is an aluminum film with a thickness of, for example, 0.05 μm.

Subsequently, in step ST12 illustrated in FIG. 7A, an inorganic film 70such as a silicon oxide film (SiO₂) is formed through a PEVCD method orthe like (refer to FIG. 9C), and thereafter, in step ST13 illustrated inFIG. 7B, in a state in which a resist mask is formed on a surface(surface on a side opposite to the wafer 10) of the inorganic film 70,the inorganic film 70 is patterned, and an etching stopper layer 71 of aplane shape which is the same as the mirror 51 is formed (refer to FIG.9D). Thereafter, the resist mask is removed. Subsequently, in step ST14illustrated in FIG. 7C, the second conductive film 560 and thereflective metal film 570 are patterned by using the etching stopperlayer 71 as a mask, and thereby the mirror 51 is formed (refer to FIG.9E). As a result, the conductive layer 56 for a mirror is formed by aportion remaining in the second conductive film 560, and the reflectivelayer 57 for a mirror is formed by a portion remaining in the reflectivemetal film 570. The steps ST12, ST13, and ST14 are a second patterningstep.

Subsequently, in step ST15, the wafer 10 is divided into a plurality ofsubstrates 1, each having a size of a single piece.

Subsequently, in step ST16 (step of removing a sacrificial layer)illustrated in FIG. 7D, the first sacrificial layer 211 and the secondsacrificial layer 221 are removed by performing plasma etching or thelike. At this time, the etching stopper layer 71 is removed. As aresult, the electro-optical device 100 is obtained.

Main Effects of the Present Embodiment

As described above, in the present embodiment, the mirror support post(second support post) 52 faces the concave portion 520 at a sideopposite to the substrate 1, but the concave portion 520 is filled witha resin. Accordingly, a large dent is hardly formed on a surface of themirror 51. In addition, in the present embodiment, the reflective metalfilm 570 is formed on a surface which becomes a continuously planarizedsurface through a planarization process, and thus a dent is hardlyformed on the surface of the mirror 51. Thus, it is possible to increaseutilization efficiency of light, and to prevent contrast from beinglowered due to scattering at the mirror 51.

In addition, since the conductive layer 56 for a mirror is thicker thanthe reflective layer 57 for a mirror, electrical resistance of themirror 51 becomes small, and thus it is possible to reliably apply aproper potential to the mirror 51. Even in this case, the sum of thethicknesses of the conductive layer 56 for a mirror and the reflectivelayer 57 for a mirror is from 0.2 μm to 0.5 μm, and thus the thicknessis the same as the thickness in a case in which the mirror 51 is formedas a single film, and the mirrors 51 is not heavy. Therefore, it ispossible to properly drive the mirror 51.

Modification Example of the Embodiment

In the above-described embodiment, it is preferable that aphotosensitive resin such as a photosensitive polyimide or the like isused as the resin 41, and in this case, the resin 41 can remain only inthe concave portion 520 by the exposed pattern. Thus, in a case in whicha height difference between a height from the torsion hinge 35 to asurface of the resin 41 at a side opposite to the substrate 1, and aheight from the torsion hinge 35 to a surface of the flat plate 53 ofthe conductive layer 56 for a mirror at a side opposite to the substrate1 is equal to or less than 0.2 μm, a decrease of utilization efficiencyof light and a decrease of contrast due to scattering at the mirror isnot noticeable. Thus, it is possible to omit the planarization process.

In addition, it is preferable that the resin 41 has conductivity, and inthis case, electrical resistance of the mirror 51 is substantiallysmall, and thus, it is possible to reliably apply a proper potential tothe mirror 51. It is possible to use polyacetylene, polythiophene,polypyrrole, polyaniline, or the like as a specific material of theresin 41. In addition, if the resin 41 has conductivity, a stablematerial, which has a larger electrical resistance than that ofaluminum, can be used for the conductive layer 56 for a mirror. It ispossible to use titanium, titanium nitride or the like as a specificmaterial of the conductive layer 56 for a mirror.

What is claimed is:
 1. An electro-optical device comprising: asubstrate; a torsion hinge disposed above the substrate; a conductivelayer disposed above the torsion hinge; a support post which protrudesfrom the conductive layer to the torsion hinge, and which includes aresin, the support post having a concave portion with the resin fillingthe concave portion; and a reflective layer which completely covers asurface of the conductive layer and the resin, the reflective layerdirectly contacting the resin, wherein a height difference between aheight from the torsion hinge to a surface of the resin at a sideopposite to the substrate and a height from the torsion hinge to asurface of the conductive layer at a side opposite to the substrate isequal to 0.2 μm or less, and wherein a depth of the support post islarger than an inner diameter of the support post.
 2. An electro-opticaldevice comprising: a substrate; a torsion hinge disposed above thesubstrate; a flat plate disposed on the torsion hinge; a supportingportion in which a resin is filled in a recess protruding from the flatplate toward the torsion hinge; and a reflective layer which completelycovers a surface of the flat plate in a plan view, a whole of thereflective layer overlapping the flat plate, wherein a height differencebetween a height from the torsion hinge to a surface of the resin at aside opposite to the substrate and a height from the torsion hinge to asurface of the flat plate at a side opposite to the substrate is equalto 0.2 μm or less.
 3. An electronic apparatus comprising: theelectro-optical device according to claim 1; and a light source unitwhich emits light source light to the reflective layer.
 4. An electronicapparatus comprising: the electro-optical device according to claim 2;and a light source unit which emits light source light to the reflectivelayer.
 5. An electro-optical device comprising: a substrate; a torsionhinge disposed above the substrate; a conductive layer disposed abovethe torsion hinge; and a reflective layer disposed on the conductivelayer, wherein the conductive layer includes a support post and flatplate, the support post is formed continuously with the flat plate,protrudes toward the torsion hinge and contacts the torsion hinge, thereflective layer contacts the flat plate, a whole of the reflectivelayer overlapping the conductive layer and A>B, wherein A is a thicknessof the flat plate, and B is a thickness of the reflective layer.
 6. Theelectro-optical device according to claim 5, wherein the support post isfilled with a resin.
 7. The electro-optical device according to claim 6,wherein the resin is surrounded by the support post and the reflectivelayer.
 8. The electro-optical device according to claim 6, wherein thereflective layer contacts the resin.
 9. The electro-optical deviceaccording to claim 2, wherein the flat plate and the supporting portionare made of conductive material.